Gritters are out on roads across Cornwall and will continue into Tuesday morning, highways bosses say.
Overnight snow on Sunday caused problems on roads around the north and east of the county on Monday.
Temperatures are expected to drop to -3C and widespread ice was possible, the Met Office said.
Cornwall Council's County Highways Department said its salting work included gritters being out in the early hours of Tuesday.
The two main trunk roads between Cornwall and Devon, the A38 and the A30, were described as "atrocious" and "dangerous" on Monday after snowfalls.
Snow also affected Callington, Bude and Penwithick.
Newquay Airport was open on Monday, but travellers were advised of possible disruption to flights.
Outbreaks of snow had moved away from south west England, but icy conditions and freezing fog patches were possible on Monday night, the Met Office said.